OMV Exploration & Production

Move & More.

The Distribution of a Hydrocarbon System

IEA Workshop and Symposium 2009Canberra, 04/21/23

K.Potsch, C.Zach, OMV E&P

2 |OMV E&P, Klaus Potsch, 21. April 2023

Overview

Problem: How to discribe the „Plus-Fraction“ of a hydrocarbon system

Medium and long distributions Chromatograms Mathematical treatment of distributions Various examples Way ahead, summary

3 |OMV E&P, Klaus Potsch, 21. April 2023

Problem = Plus-Fraction

Plus-Fraction = last component

1.E-01

1.E+00

1.E+01

0 5 10 15 20 25 30 35 40 45

single carbon number

mo

lar

per

cen

tag

e

4 |OMV E&P, Klaus Potsch, 21. April 2023

Problem = Plus-Fraction

Plus-Fraction = last component, long distributions

1.E-03

1.E-02

1.E-01

1.E+00

1.E+01

0 20 40 60 80 100 120

single carbon number

mo

lar

per

cen

tag

e

5 |OMV E&P, Klaus Potsch, 21. April 2023

Chromatograms

How to get the scn-distribution

0 5 10 15 20 25 30 35 40 45 50

minutes

arb

itra

ry u

nits

6 |OMV E&P, Klaus Potsch, 21. April 2023

Chromatograms

Tail end

45 46 47 48 49 50 51

minutes

arbi

trar

y un

its

7 |OMV E&P, Klaus Potsch, 21. April 2023

Analytical method

2 GC runs, bridging compound = n-alkane between C10 and C15.

Lower boiling components: Agilent 6890 GC + HP ChemStation fused silica capillary column (CP Sil

8.25m x 0.32mm, 0.25µm) carrier gas = Hehigh molecular weight compounds (up

to C120) with HTGC Agilent 6890 GC + AC SimDis

Software Column HP-1 (5m x 0.53mm,

0.09µm film thickness) + programmable temperature vaporizer (PTV injector).

Samples diluted in carbon disulfide.

-50

0

50

100

150

200

250

300

350

400

450

500

0 10 20 30 40 50 60

time [min]

tem

per

atu

re [

C]

NTGC

HTGC

8 |OMV E&P, Klaus Potsch, 21. April 2023

Mathematical treatment of distributions

-function [Whitson]

7

/exp1

CM

MMMp

0

0

1

0

7

7

exp

MM

MMt

ttMM

Mp

C

C

Simpler form (x=snc)

01

01 ,expxx

xxtttCxp

9 |OMV E&P, Klaus Potsch, 21. April 2023

-function [Whitson]

0.01

0.1

1

0 0.5 1 1.5 2 2.5 3

t

Gam

ma

alpha=0.5

alpha=1.0

alpha=2.0

10 |OMV E&P, Klaus Potsch, 21. April 2023

-function [Whitson], sample #1: gasoil

0

2

4

6

8

10

12

14

5 10 15 20 25 30

single carbon number (scn)

perc

enta

ge

-16

-14

-12

-10

-8

-6

-4

-2

0

2

4

ln(p

erce

ntag

e)

data

Gamma

ln(data)

ln(Gamma)

11 |OMV E&P, Klaus Potsch, 21. April 2023

-function [Whitson], sample # 2: VB-oil

0

1

2

3

4

5

6

7

8

5 10 15 20 25 30 35 40

single carbon number (SCN)

per

cen

tag

e

y=data

Gamma pdf

12 |OMV E&P, Klaus Potsch, 21. April 2023

Mathematical treatment of distributions

Gaussian log-normal distribution

2

maxlnln

2

1exp

d

xxCxp

0

1

-4 -3 -2 -1 0 1 2 3 4

normal pdf

log-normal pdf

d

y=0.6065

13 |OMV E&P, Klaus Potsch, 21. April 2023

Sample # 3: VB lean gas condensate

-4

-3

-2

-1

0

1

2

3

4

5 7 9 11 13 15 17 19 21 23 25

single carbon number (SCN)

ln(p

erce

nta

ge)

y=data

Gamma pdf

Gln pdf

14 |OMV E&P, Klaus Potsch, 21. April 2023

Mathematical treatment of distributions

Multiple Gaussian log-normal distribution

i i

ii d

xxCxp

2

max,lnln

2

1exp

15 |OMV E&P, Klaus Potsch, 21. April 2023

Sample #4: VB light oil

0

2

4

6

8

10

12

14

16

5 7 9 11 13 15 17 19

single carbon number (SCN)

per

cen

tag

e

y=data

sum

main peak

lower peak

upper peak

16 |OMV E&P, Klaus Potsch, 21. April 2023

Sample #5: VB oil

-6.0

-5.0

-4.0

-3.0

-2.0

-1.0

0.0

0 10 20 30 40 50 60 70 80 90 100

SCN

ln H

CD

data

17 |OMV E&P, Klaus Potsch, 21. April 2023

Individual HCD functions

Turned hyperbola, 3 constant equation

maxmax

ln,lnHCD

HCDy

SCN

SCNx

11 2

322132154 xaaaxaaaaay

.

.1

,1 2

542

12

11

a

aa

a

aa

18 |OMV E&P, Klaus Potsch, 21. April 2023

Sample #5: VB oil

-6.0

-5.0

-4.0

-3.0

-2.0

-1.0

0.0

0 10 20 30 40 50 60 70 80 90 100

SCN

ln H

CD data

hyperbolic

Gauss log-normal

Gamma

19 |OMV E&P, Klaus Potsch, 21. April 2023

Sample #6: VB oil, (large reservoir)

-8

-7

-6

-5

-4

-3

-2

-1

0

1

0 10 20 30 40 50 60 70 80 90 100 110 120

single carbon number

ln (

per

cen

tag

e)

data

20 |OMV E&P, Klaus Potsch, 21. April 2023

Individual HCD functions

Another 3-constant function, exponential type

maxmax

332

23321

ln,

expexp1

lnexp1

data

datay

SCN

SCNx

xCCCx

CCCCCy

rr

21 |OMV E&P, Klaus Potsch, 21. April 2023

Sample #6: VB oil, (large reservoir)

-8

-7

-6

-5

-4

-3

-2

-1

0

1

0 10 20 30 40 50 60 70 80 90 100 110 120

single carbon number

ln (

per

cen

tag

e)

data

fit

Gauss log-normal

Gamma

22 |OMV E&P, Klaus Potsch, 21. April 2023

Application

Extend the distribution to fulfill

x

dxxp1

1)(

Find functions for and M

Calculate the pseudo porperties

,),()(1

x

l dxCxxp

x

Ml dxCxMxpM1

),()(

23 |OMV E&P, Klaus Potsch, 21. April 2023

The End

Questions?